Electromagnetic separator



May 14, 1.929. J. BlNG nmacfraoumumm snr/muon 2 Sheets-Sheet l Filed Jan. 5, 1927.

May 14, 1929. J, BING ELEGTROMAGNETIC sEPARA'ron 2 sheets-sheet 2 Filed Jan. 6, 192'? faggi@ fnvenfor; Julius ,Bin

E7 /zz s l J MM QSWWM Fate/enter] May 14, 1929.

vuNiTED STATES PATENT oFFlc-E.

G. M. B.' H. EISENACI-I SPEZIALFABRIK EISENACH, GERMANY.

FR ELEKTROMAGNET-APPARATE, OF

ELECTROMAGNETIG SEP-ARATOR.

Application filed January 6, 1927, Serial No. 159,394, and iii Germany April 10, 1926.

My invention relates to electro-magnetic separators in which the introduction into the magnetic ield of the material to be separated and also the carrying of it out of the field, are effected with the aid of a drum, which surrounds a stationary magnetic system and rotates relatively thereto. The in` vention 4particularly .has reference t0 such separators of this type in which, as described in my earlier Patent Nr. 1,541,915 the magnetizable particles of the material to be separated, While traversing the magnetic field, are caused to repeatedly move to and fro so that their adhesion is loosened and the non-magnetizable particles are set free so that they can fall away unhindcred While the magnetizable particles adhering i to the rotating drum are carried by it out of the magnetic field into a neutral zone, where they can fall away separately.

rlFhese separators show the draw back that sometimes small ,quantities of the magnetism remaining in the drum jacket having left the magnetic field prevent the particles carried along by the rotating drum from falling away, especially if such particles are very minute. To obviat'e this disadvantage l arrange on the neutral side of the separator a separate magnetic system having a polarity opposite to that of the main system. regulating the exciting current of this auxiliary magnetic system correspondingly the said permanent magnetism may be completely compensated,.so that the magnetic particles adhering to the drum will ffall away at any rate.

My invention is illustrated by way of example in the accompanying drawing, in which Figure 1 is a preferred constructional form of the new separator, the left-hand side of the` figure being in elevatiomthe l right-hand side in axial sectional elevation and the middle showing a side elevation of the magnet body with the drum jacket removed.

Figure 2 is a section on the line ll-H in Figure 1.

Figure 3 shows in amore conventional manner another constructional form of the separator in a position turned about 90 relatively to that represented in Figure 1; the right-hand side of the ligure being in elevation, the left-hand side in axial section and the middle showing aside elevation of the `,magnet bodies with the drum jacket removed. Figure 4 shows one of the exciting windings in perspective.

Figure 5 is a diagram of the exciting circuits. A

The separator consists essentially of the stationary magnetic system 1, and of the drum 2 enclosing this system. The magnet system 1 surrounds the shaft 3, which rests at its ends in bearings 4, et and is prevented from being rotated by the holder 5. rll`he middle thickened part of the shaft 3` carries, in lthe constructional form illustrated, three magnet bodies 6 keyed firmly to the sha-ft. 0f these magnet bodies the two outer ones, 6a and 6b are unilateral, while cally constructed. The two outer or lateral magnet bodies 6a and 6b each comprises a. hub part, 7a and Xb respectively, a sector or disc-shaped part, 8a and 8" respectively, projecting therefrom radially, and a pole part 105L and 10b respectively consisting of a plurality of inwardly directed pointed teeth or projections, 9a and 9" respectively, and having a coaxial cylindrical outer surface. In the ease of the middle magnet body 6C the disc part 8c is fitted in the middle to the hub body and the pole part 10C, the outside of which likewise lies in the above mentioned cylindrical surface, is symmetrically constructed in so far as the pointed teeth 9e project towards both sides ofthe central plane in an axial direction. There is -however a lack of complete symmetry, in so far as the teeth on the one side do not lie exactly opposite to the teeth on the other side, the teeth on the two sides being arranged in staggered relationship to one another.

The teeth 92L and 9b of the outer pole body are also staggered relatively to the teeth 9 of the central pole body 6", in such a way as to engage in the intervening spaces formed by the teeth 9c, while conversely the teeth 9c engage in the intervening spaces between the teeth 9a and between the teeth 9b of the lateral magnet bodies 6a and 6b respectively. Between the substantially parallel edges of the opposing teeth are left certain distances, which are designated 11 in Figure 1. The disc parts 8, as well as the pole parts 1() of the magnet bodies 6, in a known manner, as

out the entire periphery, but only. form sectors which, as the dotted lines indicate, ex-

` tend round at both ends somewhat beyond the axial central plane `in question. The three magnet bodies 6, 6b and 6c form together two separate magnetic main systems, which have however a common exciting coil 12. This exciting' coil is made by winding the requisite number of turns of wire into a longitudinal closed loop, the individual turns lying'in substantiallyr parallel planes, and by then bending the arcuate end parts of these loops back through a right angle, thus producing the formation illustrated in Figure 4, which is then slid with the arcuate parts over the hub parts 7 of the magnet bodies, while the straight parts 13 connecting them come to lie along the shaft 3 andf the radialprear sides of the segments 8. The exciting current is supplied to the winding 12 by means of a lead 16 passing through holes 15 bored in the shaft 3 and in the magnet bodies.

The exciting of the two magnetic systems with the aid of a common coil of the construction described offers substantial advantages. In the first place it requires less copper than two separate windings. Above all,

it reduces the excessive and harmful leakage which occurs in the case of annular windings on the rear side of the magnetsectors 8 and which causes the magnetic field to extend in reality in rather considerable strength out beyond the ends of the sectors in a. peripheral direction and causes the magnetic particles of the material to be carried along beyond the actual boundaries of the separation zone, which of course impairs the satisfactory working of the separator.

In order to further reduce the harmful action of the magnetic leakage as well as the permanent magnetism within the magnetizable parts of the drum jacket an auxiliary magnetic system 24 is arranged opposite the middle of the main s stem within the space left by the ends of t e exciting coil 12, 13. This auxiliary system comprises a core piece 25 surrounded by an auxiliary exciting coil 26 and secured to the hub body of the main magnetic system. The outer end of the core piece has attached thereto an auxiliary pole part 27 the outside face ,of which lies sub'- stantially in the same cylindrical surface as that of the main pole pieces 10a, 10b, 10C.

The construction of the magnet bodies as described hereinbefore enables the separator to be conveniently assembled and taken to pieces. Also types of separators of greater length easily admit ofbeing manufactured by the aid of magnet bodies of the construction described. If it is desired to build a' separator of greater length and at the same time of greater capacity, all that is necessary 4vertex of the drum.

ies 6, 6 of the construction described on to a correspondingly prolonged shaft, as illustrated in Figure 3. Also a corresponding number of additional auxiliary magnets 24 are provided in this case.

The drum 2 of the separator comprises essentially the two end shields 17 and 18, which are rotatably supported on the parts of the shaft 3 located between the magnet bodies within the drum and the bearings 4, 4. The two shields 17, 18 are connected with one another by an inner cylindrical jacket 19, which is mounted at its ends on inwardly directed flange-like projections 20 on the shields 17 and 18. The jacket may consist of non-magnetizable material, such as brass, or of magnetizable material. In the latter case either the thickness of the jacket is kept very small, so that it takes up no appreciable -number of lines of force, or else a sheet material ofvery low magnetic conductivity or permeance is used, such as manganese steel. The jacket 19 is provided with a covering which is divided stripwise into magnetizable and non-magnetizable material. The covering may be made for example by winding wires of quadrilateral cross section side by side on the acket 19 into the form of a flatthreaded screw. This is done preferably with wires in pairs,lone quadrilateral wire, such as 21, consisting of magnetizable material, iron for example, and the adjacent quadrilateral wire, such as 22, of non-magnetizable materia-l, for instance brass. The adjacent turns of the winding are preferably soldered or welded on one another and also to the drum jacket 19, and then turned up smooth on the outside. The left-hand drum end shield 18 `is provided with a toothed ring 23, which gears with a toothed wheel not shown, by means of which the drum is rotated in the direction of the arrow.

Above the drum there is mounted a chute or channel 28 by means of which the material to be sepa-rated is supplied to a point of the drum which lies somewhat beyond the Beneath the lower side of the drum a container 29 is provided, the

.length of which corresponds to the active The container is subdivided into three compartments by two vertical partitions 30, 31. The left hand compartment 32 serves to receive the non-magnetic particles, while in the middle compartment 33 the feebly magnetic and in the right hand compartment 3ft the strongly magnetic particles are gathered. The partitions have extensions 35, 36. Each one and the same source 37.

of these extensions comprises a blade'part 35a and 36a respectively shiftable relatively to it and projecting near the circumference of the separator drum. The shiftable parts L1 and 36a may be adjusted to the lower parts and secured in the position desired by means of set screws 40,41 which are passed through slots provided in the adjacent ends of the blade parts and the upper parts of the extensions. Besides, the projections 35, 36 may be swung about pivots 42, 43 to adjust their top ends in different positions relatively to the separator` drum. Normally the positions of the extensions are so that the left-hand extension represents substantially a vertical tangential line to the left-hand drum side, While the right-hand extension 36 lies substantially in a vertical plane going through the axis of the drum. 4 As may be seen from Figure 5 the exciting coil l2, 13 of tlie main magnet system and the exciting :coil 26 of the auxiliary magnet system are fed with current in parallel from Each of the exciting circuits comprises a separate regnlating resistance. 38 denotes the resistance of the main circuit 39, and that of the auxiliary circuit 44.

The operation of the separator is as fo'llovvs: rlhe material to be separated, preferably in a nely divided state, is supplied by means of the feed channel 28 on the upper side of the drum 2.l It then travels with the drum in the direction of the arrow in Figure 2 through the magnetic field. The magnetizable particles ofthe 'material are in that case particularly strongly attracted at the outer edges of the strips 21 of magnetizable material, Where the lines of force concentrate. Here roWs off-clusters of magnetic particles form, Which however, While travelling through the magnetic field continually changetheir direction, since the strength of the field of forcetraversed in the travelling as Well as their polarity are also incessantly changing, the inductive effect of themagnet poles on the magnetizable strips of the drulnjacket covering :changing both with the dimensions and With the position and boundaries Vof the parts of the magnet poles that are for the time being covered. This phenomenon has the result that the magnetic particles adhering to the edges of the strips 21 are to a certain extent shaken to and fro and loosened, so that the non-magnetizable particles enclosed by them, have an ample opportunity during the vtraversing of the magnetic iield, to become free. These particles, therefore, Will fall out of the remaining more or less magnetizable material, as soon as the travel of the rotating drum passes into the vertical direction. The par'- ticles are gathered in the left-hand'compartment 32 of the container 29. 'The feebly magnetic particles are carried further along With the drum and Will drop out from the strongly magnetic particles under the action of the gravity Within the zone between the extensions 35 and 36 and so Will arrive in the middle section 33 of the container, While the strongly magnetic particles Will not fall away before the magnetic ield produced by the main magnet system ceases i. e; at a point beyond the lower vertex line of the drum. These particles, therefore, Will drop into the right-hand compartment 34 of the container'.

By correspondingly exciting the auxiliary magnet or magnet-s 24 by means of the adjustable resistance 38, any leakage of the main magnetic field and especially the permanent magnetism Within the magnetizable parts of the drum jacket may be compensated so as to produce a really neutral zone of the right-hand side of the drum and thus to cause all of the magnetic particles carried along by the drum into this Zone to drop off. In thismanner a very clean and effective separation of the material is obtained even when treating very feebly magnetic material.

I claim l. Electro-magnetic separator comprising: a main magnet system; a drum enclosing said magnet system and rotatable relatively to it; the magnet poles of said system lying substantially in a cylindrical surface coaxial to said drum and having edges lying obliquely to the generatrix of said cylindrical surface; said drum comprising substantially helically arranged strips consisting alternately of magnetizable and non-magnetizable material; an auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum; and means to produce Within said auxiliary system a magnetic field of a polarity contrary to that of the lnain system.

2. Electro-magnetic separator comprising: a main magnet system; a drum enclosing said magnet system and rotatable relatively to it; the magnet poles of said system lying substantially in a cylindrical surface coaxial to said drum and having edges lying obliquely to the generatrix of said cylindrical surface; said drum comprising substantially helically arranged strips consisting alternately of magnetizable and non-magnetizable material; and an auxiliary magnet system having poles lying in a cylindrical snrface coaxial and adjacent to said drum adapted to compensate the permanent magnetism originating from the influence of the main magnet system on the magnetizable strips of saiddrum.

3. Electro-magnetic separator comprising:

a main magnet system; a drum enclosing said magnet system and rotatable relatively to it; the magnet poles of said system lying substantially in a cylindrical surface coaxial to said drum and having edges lying ohliquely to the generatrix 4of said cylindrical originating from the yinfluence of the main magnet system on the magnetizablestrips of said drum; and means to regulate the magnetic intensityv of said auxiliary system independently from that of the main system.

4. Electro-magnetic separator comprising: a main magnet system having magnet poles; a drum enclosing said system and rotatable relatively to it; the` outside surfaces of said magnet poles lying substantially in cylindrical surfaces parallel to the drum surface andl having edges extending obliquely to the generatrix of said cylindrical surfaces; said drum comprising cireumferentially extending strips of alternately magnetic and nonmagnetic material; and an auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said v`drum adapted to compensate the permanent magnetism originating from the influence of the main magnet system on the magnetizable strips of said drum.

5. Electro-magnetic separator comprising a main magnet system having magnet poles; a drum enclosing said system and rotatable relatively to it; the outside surfaces of said magnet poles lying substantially in cylindrical surfaces parallel to the drum surface v and having edges extending obliquely 'to the generatrix of said cylindrical surfaces; said drum comprising circumferentially extendingstrips of alternately magnetic and nonmagnetic material; an auxiliary `magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum j ladapted to compensate the permanent magnetism originating from the influence of the main magnet system.

6. Electro-magnetic separator comprising: a main magnet system; a drum enclosing said system and rotatable relatively to it; the outer surfaces of said magnet poles lying substantially in cylindrical surfaces parallel to the surface ofsaid drum and having edges extending obliquely to generatrixes of said cylindrical surfaces; said drumhaving a covering consisting substantially of circumferentially extending strips of alternately magnetizable and non-magnetizable material; and an auxiliary magnet system havingpoles lying in a cylindrical surface coaxial and adjacent to said drum adapted to compensate the permanent magnetism originating from the influence of the magnet system on the magnetizable strips of said drum.

manent magnetism originating from the iniiuence of the magnet system on the magnetizable strips of said drum.

8. Electro-magnetic separator comprising: a main magnet system; a drum enclosing said magnet system and rotatable relatively to it; the magnet poles of said system lying in a cylindrical surface coaxial to said drum and having edges lying obliquely to the generatrix of said cylindrical surface; said drum having a covering of alternately magnetizable and non-magnetizable strips lyin adjacent one to another; pole pieces on said magnet system; the operative edges of said pole pieces and of said strips substantially crossing each other; and an auxiliary magnet system having poles lying in a cylindrical surface coaxial `and adjacent to said drum adapted to compensate the permanent magnetism originating from the infiuence of the magnet system on the magnetizable strips of said drum.

9. Electro-magnetic separator comprising: av main magnet system; a drum enclosing said system and rotatable relatively to it; the edges of the poles of said magnet system adjacent to said drum lying substantially in a cylindrical surface coaxial to said drum and extending obliquely to the axis of the drum; said drum comprising substantially circumferentially extending strips of alternately magnetizable and non-magnetizable material; an auxiliary magnet system having poles lying in a cylindrical. surface coaxial and adjacent to said druln adapted to compensate the permanent magnetism originating from the infiuence of the main mag` and adjacent to said drum adapted to partially compensate the magnetic iields of said first named bodies.

11. Electro-magnetic separator comprising: two magnet bodies; a drum enclosing said magnet bodies and rotatable relatively to them; two quadrilateral wires, one of magnetizable the other one of non-magnetizable material, and wound one adjacent to the other in the form of flat-threaded screw turns onto said drum and rigidly secured to it, a single exciting coil common to said'two magnet bodies; and a third magnet body having poles lying in a cylindrical surface coaxial and adjacent to said drum, adapted to partially compensate the magnetic fields of said first named bodies.

l2. ln an electro-magnetic separator two magnet bodies; at least one of said magnet bodies comprising two pole shoes, two sectorlike core pieces and a hub-like yoke piece; a single exciting coil common to said two magnet bodies and only partly surrounding the yoke pieces of the magnet bodies; a drum enclosing said magnet bodies and rotatable relatively to them; Asaid drum having a covering consisting of substantially circumferentially disposed strips of alternately magnetizable and' non-magnetizable material; a third magnet body within said drum opposite said pole shoes, said third magnet body secured to said yoke piece, and comprising a third pole shoe, the outside face of which lies in a cylindrical surface coaxial and adjacent to said drum and means to produce in said third magnet body a magnetism of a polarity opposite to that of the first named magnet bodies.

13. Electro-magnetic kseparator comprising: a main magnet system having poles of different polarity; a drum enclosing said magnet system and rotatable relatively to it; the poles of different polarity forming .two opposite groups of pointed teeth axially projecting in di'lt'erent directions; the pole teeth of the one group projecting into the interstices formed bythe teeth of the other group; two quadrilateral wires, one of magnetizable the other one of non-magnetizable material; said wires wound with pairs in the form of a flat-threaded screw onto said teeth of the one group projecting into the interstices formed by the teeth of the other group; two quadrilateral wires, one of magnetizable the other one of non-magnetizable material; said wires wound with pairs in the form of a flat-threaded screw onto said drum and rigidly secured to it; an auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum adapted to compensate thefpermanent magnetism originating from the inluence of the main magnet system on the magnetizable strips of said drum.

15. A separator comprising: a rotatable drum; a stationary main magnet system within said drum, the pole pieces of said magnet system extending over a part only of the periphery of said drum; a container beneath said drum; rockable wall means bet-ween` said container and the under side of' the drum, one of said wall means lying substantially in a vertical plane through the lower boundary of said pole ieces; another of said wall means arrange between said irst named'wall means and a vertical tangential plane laid on that side ot' the said drical surface coaxial and adjacent to said drum adapted to compensate the permanent magnetism in said drum.

16. A separator comprising: a rotatable drum; a stationary main magnet system within said drum, the pole pieces of said magnet system extending over a part only of the periphery of said drum; a container beneath said drum; rockable wall means between said container and the under side of the drum, one of said wall means lying substantially in a vertical plane through the lower boundary of said pole pieces; another of said wall means arranged between said first named wall means and a vertical tangential plane laid on that side of the said drum over which said pole pieces extend; means to supply the material to be separated of the top ot said drum; an auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum adapted to compensate the permanent magnetism in said drum; and means to regulate the magnetic intensity of said auxiliary magnet system independently from that of the .-main magnet system.

17. Electromagnetic separator comprising: a main magnet system; a drum enclosing said magnet system and rotatablev relatively to it; the magnet poles of said system lying substantially in a cylindrical surface coaxial to said drum and having edges lying obliquely to the generatr'ix of said cylindrical surface; said drum comprising substantially .helically arranged strips consisting alternately of magnetizable and non-magnetizable material; and an' auxiliary magnet systemhaving poles-lying in a cylindrical surface coaxial and'adjacent to said drum adapted to compensate the permanent magnetism in the magnetizable strips of said drum* Y 18. Electro-magnetic separator comprising: a main magnet system; a drum enclosing said magnet system and rotatable relatively to it; the magnet poles of said system lying substantially in a cylindrical surface coaxial to said drum and having edges lying obliquely tothe generatrix of said cylindrical surface; said drum comprising substantially helically arranged strips consisting alternately of magnetizable and non-magnetizable material; and means to compensate the permanent magnetism in the magnetizable strips of said drum lying in a cylindrical surface coaxial and adjacent to said drum. y

19. Electromagnetic separator comprising a drum a main magnet system coaxial therewith, and an auxiliary magnet system I? having poles lying in a cylindrical surface coaxial and adjacent to said drum for compensating the leakage of the magnetic field of the main magnet system.

20. Electromagneticl separator comprising a drum magnetizable and non-magnetizable parts a main magnet system coaxial therewith, and an auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum for compensating the leakage 0f the magnetic ield of the main magnet system and compensating permanent magnetism Within the magnetizable parts of the separator.

2l. A separator comprising a rotatable drum, a stationary main magnet system Within said drum, a stationary auxiliary magnet system having poles lying in a cylindrical surface coaxial and adjacent to said drum for compensating the leakage of the magnetic field of the main magnet system, and a container cooperating with said drum for receiving separated material from said drum.

22. A separator comprising a rotatable drum; a stationary main magnet system within said drum, the pole pieces of said magnet system extending over a part only of the periphery of said drum; a container' beneath said drum and having partition Walls provided with extensions consisting of upper and lower wall portions, said lower Wall portions being pivotally mounted at their lower ends on the top edges of said partition Walls, said upper Wall portions being adjustably secured to the upper ends of the lower wall portions and extensible from said upper ends; and means for supplying the material to be separated to the top of said drum.

In testimony whereof I afiix my signature.

JULIUS BING. 

